Genotypic and Phenotypic Responses of Candida albicans to Spaceflight (Micro-8) - 11.22.16

Overview | Description | Applications | Operations | Results | Publications | Imagery

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Science Objectives for Everyone
The aim of Genotypic and Phenotypic Responses of Candida albicans to Spaceflight  (Micro-8) is to assess gene expression, morphology, and virulence factors responses of Candida albicans (C. albicans) following exposure to spaceflight environment. This work aims to provide a better understanding of yeast adaptation response to extreme environments and the associated crew health risks for long-term exploration.
Science Results for Everyone
Information Pending

The following content was provided by Sheila Nielson-Preiss, Ph.D, and is maintained in a database by the ISS Program Science Office.
Experiment Details

OpNom: Micro-8

Principal Investigator(s)
Sheila Nielson-Preiss, Ph.D, Division of Health Sciences, Montana State University, Bozeman, MT, United States

Co-Investigator(s)/Collaborator(s)
Information Pending

Developer(s)
BioServe Space Technologies, University of Colorado, Boulder, CO, United States

Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
Human Exploration and Operations Mission Directorate (HEOMD)

Research Benefits
Earth Benefits, Scientific Discovery

ISS Expedition Duration
September 2014 - March 2015

Expeditions Assigned
41/42

Previous Missions
First flight of the Micro 8 payload

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Experiment Description

Research Overview
The aim of this experiment is to investigate the effects of spaceflight on cellular responses (shape and behavior) using Candida albicans (C. albicans).

Micro-8 provides an opportunity to further explore and confirm the responses of C. albicans observed during Micro-6, including observation of cell morphology, gene expression, and antifungal sensitivity.

In addition, Micro-8:

  1. Includes a pilot study to more directly evaluate virulence using human monocytes as the host for yeast infection,
  2. Determines susceptibility to the antimicrobial agent Fluconozol, in addition to Amphotericin B,
  3. Evaluates the effect of spaceflight on physiological adaptations represented by filamentation, biofilm formation, and phenotypic switching/colony morphology,
  4. Documents the differential expression of genes associated with the physiological adaptation responses.

Description
Simulating the microgravity environment has allowed investigation of cellular responses in a ground-based model and has provided insights into the impact of spaceflight on cellular behavior. Using Candida albicans (C. albicans), an opportunistic yeast pathogen, it has been demonstrated that simulated microgravity affects cell shape and behavior, with a coordinated expression of several genes associated with these specific adaptations.  Among the changes observed are a transition to a more filamentous or elongated form of the yeast, an altered structure when the yeast grows as a community in the form of a colony, and an increased resistance to the antimicrobial agent Amphotericin B. The constellation of these physiological responses is consistent with a potential increase in the virulence of this opportunistic yeast pathogen. A more complete understanding of the yeast adaptation response to extreme environments (such as microgravity) and the risks associated with potential infection is vital for long-term flight crew health and safety. The experiments flying as the Micro-8 payload provides the opportunity to further explore and confirm the responses of C. albicans observed during the Micro-6 payload flown on SpX CRS-1 in October 2012, including observation of cell morphology, gene expression, and antifungal sensitivity. The research team is also extending the research by including a pilot study to more directly evaluate virulence using human monocytes as the host for yeast infection.

The goal of the ongoing studies is to further examine the responses of C. albicans to microgravity by performing hypothesis-driven research in spaceflight conditions. The overarching hypothesis is that exposure of C. albicans to microgravity alters gene expression and morphology, consistent with a potential increase in virulence. Notably, these studies 1) will inform the value of LSMMG for predicting the physiological responses of C. albicans, 2) further explore and document the phenotypic parameters of C. albicans that are associated with pathogenicity and are altered during exposure to spaceflight, and 3) may predict conserved responses of higher eukaryotes, including humans, to spaceflight conditions.

Other objectives and aims of this investigation include:

  • The determination of the susceptibility to the antimicrobial agents Amphotericin B and Fluconozol, and the capacity for virulence following exposure to spaceflight.
  • Evaluation of the effect of spaceflight on physiological adaptations represented by filamentation, biofilm formation, and phenotypic switching/colony formation.
  • The documentation of the differential expression of genes associated with the physiological adaptation responses.

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Applications

Space Applications
The fundamental space biology experiments addresses basic questions of how life responds to gravity and space environments.

Earth Applications
These studies 1) apply to the 2011 Decadal Plant and Microbial Biology section, 2) inform the value of low-stress modeled microgravity; (LSMMG) for predicting the physiological responses of C. albicans, 3) further explore and document the phenotypic parameters of C. albicans that are associated with pathogenicity and are altered during exposure to spaceflight, and 4) may predict conserved responses of higher eukaryotes, including humans, to spaceflight conditions.

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Operations

Operational Requirements and Protocols
Late Load Early Recovery. Temperature controlled environment during launch, processing, and return. Crew interaction required to transfer payload to ISS from Space-X Dragon vehicle, as well as for activation and termination activities.
Two GAPs containing the Monocyte experiment are launched into the ISS inside CGBA at +37°C and transferred to ISS at the same temperature. Fourteen GAPs containing the Candida albicans experiment is launched in a Double Cold Bag holding temperature at +22°C. Once at the ISS, these GAPs are transferred to two CGBAs currently onboard the ISS. The samples are held at +12°C until it is time to process the experiment.

On Board ISS early operations include: Monocyte GAPs are manually activated by the crew and the experiment conducted at +37°C. At 100 hours post-activation, the experiment is terminated by the crew, transferred to MELFI, and held at -95°C or stored in CGBA at +4°C until returned to Earth. The GAPs containing Candida albicans are activated manually by the crew and processed at +30°C. The experiment is terminated manually by the crew 100 hours post-activation. GAPs are stored either in MELFI at -95°C, or within CGBA at +4°C, until return to Earth.

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Decadal Survey Recommendations

CategoryReference
Plant and Microbial Biology P1
Plant and Microbial Biology P2

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Results/More Information

Information Pending

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Related Websites

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Imagery

image NASA Image: ISS039E018752 - ESA Alex Gerst activating Micro-8 Group Activation Packs (GAPs).
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image NASA Image: ISS041E078057 - ESA astronaut Alex Gerst with Micro-8 Group Activation Packs (GAPs).
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image NASA Image: ISS041E078063 - View of the Micro-8 Group Activation Packs (GAPs).
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image Human monocytes engulf the pathogenic yeast Candida albicans in this image taken with a microscope. Scientists are studying the effect of microgravity on the response of the monocyte cells to the yeast in the Micro-8 investigation. Image courtesy of: Sheila Nielsen
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